For example, a lead-acid storage battery for automobile use supplies power to a large number of electrical parts and accessories such as a horn, lighting lamps, direction or stop indicator lamps, air conditioner, car radio, interior lamps and cigarette lighter, as well as to an engine starting circuit.
FIG. 5 is a perspective view illustrating an apperance of a conventional lead-acid storage battery 15 for automobile use, in which reference numerals 2 and 3 respectively represent a lid and a container, both of which are made of resin. The lead-acid storage battery 15 includes a pair of terminals comprising a single positive terminal 4 and a single negative terminal 5. Power supply cords for the engine starting circuit and various electrical parts and accessories are respectively connected to these terminals. Alternatively only the cord for the engine starting circuit is connected to the terminals, while the cords for various electrical parts and accessories are connected to the engine starting circuit, from which power is branched off.
A connection form with all the cords connected to the pair of terminals of the storage battery is not desirable in appearance since a large number of cords are laid on the top of the storage battery. Another problem associated with this is that replacement of the storage battery becomes troublesome because of the need to detach these plural cords.
A connection form with only the cord for the engine starting circuit connected to the pair of terminals of the storage battery necessitates all the current to flow through a single cord and accordingly requires a thick cord. Another problem is that concentration of all the current in a single cord results in great power loss during transmission.
For the connection of a large number of cords or a single, thick cord to the pair of terminals, these terminals must be greatly protruded from the top of the storage battery, which causes a problem of causing a large dead space above the storage battery.
Also, in addition to conventional electrical parts and accessories, a device for announcing the life of a storage battery, an automobile antitheft device and the like have been developed in these days. These devices also require supply of power from the storage battery and therefore a number of cords to be connected to the terminals of the storage battery is expected to be increased in the future, which results in tendency to make those problems even more apparent.
In order to address those problems, several proposals were made in such as Japanese Patent Application Laid-open No. Hei-5-258813, in which a power distribution unit made up of the combination of an external power-distribution block and a connector is mounted to the storage battery is proposed. In Japanese Patent Application Laid-open No. 2000-30689, a connection form with the terminals of a storage battery connected to electric cords via a coupler is proposed.
However, these connectional forms are expensive and require a large space for the connection of the cords.
In consideration of these problems associated with the conventional arts, it is an object of the present invention to provide a storage battery that causes a small power loss during transmission and has a desirable appearance.